Overall race leader Italian Vincenzo Nibali of Astana celebrates as he crosses the finish line to win the 18th stage of the Giro d’Italia in Polsa, Italy, on Thursday.

Photo: EPA

Italy’s Vincenzo Nibali took a major step toward overall victory in the Giro d’Italia on Thursday after powering to his first stage win at this year’s race in an individual uphill time trial.

Nibali more than doubled his overnight advantage over his closest overall pursuer, Australia’s Cadel Evans, from 1 minute, 26 seconds to a more solid margin of 4:02. Colombia’s Rigoberto Uran remained third, 4:12 back.

The last rider to start stage 18, the Astana rider surged home through to teeming rain on the 20.6km time trial from Mori to Polsa, Italy, to beat Spaniard Samuel Sanchez by 58 seconds. Italy’s Damiano Caruso was third, Uran finished sixth, while Evans slumped to 25th, 2:36 back.

“This is my first stage win here in 2013, and I and the team wanted to get this victory badly, I wanted to leave my mark on the stage wins as well as on the overall,” said Nibali, who has finished second and third in previous Giros. “These are really important advantages, it means I can take things more easily and so can my team. We can ride more calmly now.”

The fastest at the mid-stage checkpoint by 32 seconds, Nibali’s only blip was when he swerved late on one rain-sodden curve which appeared to slow him down.

“I felt good this morning even when I was doing a recon of the stage, so I thought I would be in good shape,” he said. “When the rain started, I had to be careful on the corners because I had high tire pressure so I wouldn’t slip.”

Nibali admitted that he was surprised with the lead he had managed to open up over Evans.

“I was surprised that Evans wasn’t in such good shape,” the Italian said. “I didn’t know what his condition really was, he’s been there or thereabouts throughout the stages, but I thought he would do better today. He was my big reference point today, when I saw I was gaining time on him, I pushed even more.”

Yesterday’s 19th stage was canceled due to snow along the route, leaving just one more difficult leg for Nibali to navigate.

Organizers said there were “adverse weather conditions and, in particular, snow on the stage route in its entirety.”

The 19th stage in the 21-leg race had already been altered because of avalanche threats and sub-zero temperatures. With snow and ice predicted, the Gavia and Stelvio passes were cut from the route.

“The organizers have put the security of riders first and the UCI supports their decision,” said Pat McQuaid, president of the international cycling federation. “The riders have been racing in very difficult conditions this week, but today those conditions are just too extreme.”